Go to settings >Apps >Download manager, clear data and clear cache then force stop.
Similarly clear cache, data and force stop download, playstore then restart your phone.

Use Google Apps installer in the app store to Uninstall the Google Apps and install again all of them with that app and restart your mobile it will works maximum time if it doesn't work then restore factor your mobile or re install the flyme OS by clearing app data this will works compulsory but before doing this backup your app data

same for me